Small Issue, Need some more experienced help. Options

[bsamps4]

The good: Car starts up and and warms up, and drives great.

The bad: when under load the temp gauge lowers about 1/8th of an inch under heavy boost. I'm only running around 7psi for break in. I also have a tiny coolant leak, very tiny. and a low temp thermostat from ATS. after a few seconds of driving normaly (no boost) the car begins to creep back to normal temp, and it will remain there. Even at a stop light. So I don't know if this leak under boost is causing the temp gauge to read incorrectly. Perhaps an air bubble created from the leak is causing this?

Just need some thoughts from you guys. Any advice would be appreciated.

Issue #2:

When the car is at idle it's reading around 15 vacuum, I'm under the impression that this should be more what 21. From time to time the car will idle around 1100, and when it does the vacuum is at around 20. The idle will drop to about 600 when the car reads 21.

Scenario: I stop at stop light car idles at 1100-1200 with vacuum at -20. After about 30 seconds car sputters slightly, and vacuum raises to -15 and idle drops to 600ish.

WHAT'S THE DEAL WITH THIS!!!

[bsamps4]

I certainly hope not. It's a brand new thermostat. That's not to say it couldn't be defective, but I've had a bad thermostat before that was frozen open, and the car would never make it to operating temperature. I've tracked my coolant leak to the top radiator hose where it connects to the water neck that houses the coolant temperature sensor. It only leaks during heavy load (5th gear boost pull), and it is during these heavy load pulls that my temp sensor starts to react. I'm thinking i'm getting air into the system which could be causing a mis-read in engine temp. What are your thoughts on this theory?

Also it seems like it's not boosting as hard. I'm thinking my vacuum leak may be getting worse. How would you use starting fluid to locate the leak?

I had another theory about this....I'm using the stock BOV, and I'm venting it atmospherically. This may be resulting in a leak if it's not getting vacuum to where it used to connect to the air box....perhaps it's not shutting all the way due to this...???